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6. ROM
Rev.3.00 Jul. 19, 2007 page 134 of 532
REJ09B0397-0300
Set pins to boot mode and
execute reset start
Host transmits data (H'00)
continuously at prescribed bit rate
Chip measures low period of H'00 data
transmitted by host
Chip calculates bit rate and sets value
in bit rate register
After bit rate adjustment, chip transmits one
H'00 data byte to host to indicate end of
Host confirms normal reception of bit rate
adjustment end indication (H'00), and
transmits one H'55 data byte
After receiving H'55, chip transmits
one H'AA data byte to host
Host transmits number of programming
control program bytes (N), upper byte
followed by lower byte
Chip transmits received number of bytes
to host as verify data (echo-back)
Host transmits programming control
program sequentially in byte units
Chip transmits received programming
control program to host as verify data
Transfer received programming control
program to on-chip RAM
End of transmission
Check flash memory data, and if data has
already been written, erase all blocks
After confirming that all flash memory data
has been erased, chip transmits one H'AA
Execute programming control program
transferred to on-chip RAM
Note: If a memory cell does not operate normally and cannot be erased, one
H'FF byte is transmitted as an erase error, and the erase operation and
subsequent operations are halted.
Figure 6.8 Boot Mode Execution Procedure
Start
adjustment
n = 1
(echo-back)
No
n = N ?
Yes
byte to host
n + 1→ n
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